Alternating Current Is More Fatigable Than Pulsed Current in People Who Are Healthy: A Double-Blind, Randomized Crossover Trial

Abstract Objective Tolerance level and rapid fatigue onset are limitations in the use of neuromuscular electrical stimulation (NMES) as an electrotherapeutic resource rehabilitation training protocols; however, it is unclear if pulsed current (PC) alternating (AC) produce different levels when applied at submaximal contraction level. The purpose this study was to compare discomfort between PC AC during a protocol people who healthy. Methods In double-blind, randomized crossover trial conducted laboratory setting, 30 male volunteers [23.23 years age (SD = 4.59)] performed 2 protocols (with 7-day interval) order: (pulse duration milliseconds, pulse frequency 100 Hz) (2.5 kHz, 0.4 burst Hz). NMES currents were knee extensor motor point dominant limb. consisted 80 evoked contractions (time on:off 5:10 seconds) lasted 20 minutes. maintained constant intensity throughout protocol. primary outcome measures maximal voluntary isometric contraction, index (evoked torque decline), fatigability (number for 50% drop evoked-torque from start), total torque-time integral (TTI), decline TTI, Results 2.5 kHz demonstrated higher post-fatigue, index, (ie, fewer reach smaller TTI compared with PC. No between-currents difference observed Conclusion less fatigable than kHz. Impact Based on study, preferred choice goal generate muscle work, mechanical load, both athletes healthy programs disease or injury.